Hi guys,

What can you say about the relationships of my database model,
LMS-DataBase-Model-ver2.jpg

Please disregard the datatypes, I'm only interested to hear from you guys regarding the relationships of the tables.
For example on 'Classes' table It is a FK on 'Parts' and 'Media' tables is this fine?
One parent table two children tables is this okay.

Also any improvements you can suggest like the look-up table or junction table.
Or flaws that you will notice?

Thanks in advance.